The present invention relates to a protector for mounting on a leading cord chip. More particularly, it relates to a protector for mounting on the leading cord chip in which an operator's fingers or the like cannot contact a plug projecting from the top of the leading cord chip.
Generally, a leading cord chip is a connecting portion mounted on the top of the leading cord, which is connected with an electrode or another apparatus. The above leading cord is a cord through which an electrocardiogram signal from a patient is conveyed. The conventional leading cord chip has a metallic plug 11 projecting from the top thereof, as shown in FIG. 1A. A leading cord 13 is connected to the plug 11, which protrudes through a shell 12.
Methods for using the leading cord chip are as follows.
One method connects the plug 11 with a durable electrode which is not disposable but which is usable for a relatively long time. For example, the electrode may be a band-type limb electrode or an absorption-type breast electrode. The electrode connects the leading cord 13 with an electrocardiograph.
On the contrary, another method connects the leading cord 23 with a disposable electrode, for example, a magnet-type breast electrode, and connects the plug 11 with the relay portion of a cord connected with the electrocardiograph.
In both of the above-described methods, the electrocardiogram signal, which is led from the patient through the electrode, is input into the electrocardiograph device through the leading cord chip, as shown in FIG. 1A, whereby the electrocardiogram signal is input accordingly.
However, in the leading cord chip shown in FIG. 1A, the following problem results. That is, since the plug 11 is exposed, it may be inserted erroneously into the female pin 21A of a connector 21, etc. connected to a commercial electric power source.
To solve the above problem, as shown in FIG. 1B, a protector 30 has been provided having two cover portions 30A and 30B which are situated at both sides of a plug 20 projecting from a cord fixing portion 10.
With the protector 30, it is impossible to insert the plug 20 erroneously into the female pin 21A of a connector 21 of a commercial electric power source. Consequently, the protector 30 avoids the potential problem of current flowing into the patient through the plug 20.
However, since the interval between the cover portions 30A and 30B is relatively large, the protector 30 has the following problem. That is, fingers, etc. of the operator, patient, etc. may contact the plug 20 through the cover portions 30A and 30B. Consequently, the operator is exposed to the current. For example, when electrocardiogram signal is output by a band-type limb electrode or an absorption-type breast electrode, all the leading cords are not always used.
Hence, some of the leading cord chips are not used. In this case, when the operator's finger contacts one of the leading unused cord chips, the finger enters the chip through the cover portions 30A and 30B. As a result, the operator's finger contacts the plug 20, as shown in the left drawing of FIG. 1C.
Further, many electrical apparatuses (i.e., a computer, air conditioner, freezer, etc.) are placed in the patient's room. These electrical apparatuses and medical instruments of the above-mentioned electrocardiograph, etc. are commonly grounded. Moreover, standards on voltage or current, etc. are not uniform between the above-mentioned electric apparatuses and the medical instruments. Accordingly, leakage current from the electric apparatuses may be input into the plug 20 along the patient's body, and may enter the patient through the leading cord chip.
Further, the plug 20 contacts the iron frame 40 of a bed (as shown in the central drawing of FIG. 1C), or the plug 20 contacts the corner of a metallic desk 50 (as shown in the right drawing of FIG. 1C). In the above-described cases, leakage current from the electric apparatuses may be input to the plug 20 along the iron frame 40 or the metallic desk 50, whereby it enters a patient through the leading cord chip being used.